Currently, there exist a set of if...else statements in the
mhi_pm_disable_transition() function which make handling system
error and disable transitions differently complex. To make that
cleaner and facilitate differences in behavior, separate these
two transitions for MHI host.
Signed-off-by: Bhaumik Bhatt <bbhatt@xxxxxxxxxxxxxx>
---
drivers/bus/mhi/core/pm.c | 159 +++++++++++++++++++++++++++++++++++++++-------
1 file changed, 137 insertions(+), 22 deletions(-)
diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
index 1d04e401..347ae7d 100644
--- a/drivers/bus/mhi/core/pm.c
+++ b/drivers/bus/mhi/core/pm.c
@@ -444,7 +444,7 @@ static int mhi_pm_mission_mode_transition(struct mhi_controller *mhi_cntrl)
return ret;
}
-/* Handle SYS_ERR and Shutdown transitions */
+/* Handle shutdown transitions */
static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl,
enum mhi_pm_state transition_state)
{
@@ -460,10 +460,6 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl,
to_mhi_pm_state_str(mhi_cntrl->pm_state),
to_mhi_pm_state_str(transition_state));
- /* We must notify MHI control driver so it can clean up first */
- if (transition_state == MHI_PM_SYS_ERR_PROCESS)
- mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_SYS_ERROR);
-
mutex_lock(&mhi_cntrl->pm_mutex);
write_lock_irq(&mhi_cntrl->pm_lock);
prev_state = mhi_cntrl->pm_state;
@@ -502,11 +498,8 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl,
MHICTRL_RESET_SHIFT,
&in_reset) ||
!in_reset, timeout);
- if ((!ret || in_reset) && cur_state == MHI_PM_SYS_ERR_PROCESS) {
+ if (!ret || in_reset)
dev_err(dev, "Device failed to exit MHI Reset state\n");
- mutex_unlock(&mhi_cntrl->pm_mutex);
- return;
- }
/*
* Device will clear BHI_INTVEC as a part of RESET processing,
@@ -566,19 +559,142 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl,
er_ctxt->wp = er_ctxt->rbase;
}
- if (cur_state == MHI_PM_SYS_ERR_PROCESS) {
- mhi_ready_state_transition(mhi_cntrl);
- } else {
- /* Move to disable state */
- write_lock_irq(&mhi_cntrl->pm_lock);
- cur_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_DISABLE);
- write_unlock_irq(&mhi_cntrl->pm_lock);
- if (unlikely(cur_state != MHI_PM_DISABLE))
- dev_err(dev, "Error moving from PM state: %s to: %s\n",
- to_mhi_pm_state_str(cur_state),
- to_mhi_pm_state_str(MHI_PM_DISABLE));
+ /* Move to disable state */
+ write_lock_irq(&mhi_cntrl->pm_lock);
+ cur_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_DISABLE);
+ write_unlock_irq(&mhi_cntrl->pm_lock);
+ if (unlikely(cur_state != MHI_PM_DISABLE))
+ dev_err(dev, "Error moving from PM state: %s to: %s\n",
+ to_mhi_pm_state_str(cur_state),
+ to_mhi_pm_state_str(MHI_PM_DISABLE));
+
+ dev_dbg(dev, "Exiting with PM state: %s, MHI state: %s\n",
+ to_mhi_pm_state_str(mhi_cntrl->pm_state),
+ TO_MHI_STATE_STR(mhi_cntrl->dev_state));
+
+ mutex_unlock(&mhi_cntrl->pm_mutex);
+}
+
+/* Handle system error transitions */
+static void mhi_pm_sys_error_transition(struct mhi_controller *mhi_cntrl)
+{
+ enum mhi_pm_state cur_state, prev_state;
+ struct mhi_event *mhi_event;
+ struct mhi_cmd_ctxt *cmd_ctxt;
+ struct mhi_cmd *mhi_cmd;
+ struct mhi_event_ctxt *er_ctxt;
+ struct device *dev = &mhi_cntrl->mhi_dev->dev;
+ int ret, i;
+
+ dev_dbg(dev, "Transitioning from PM state: %s to: %s\n",
+ to_mhi_pm_state_str(mhi_cntrl->pm_state),
+ to_mhi_pm_state_str(MHI_PM_SYS_ERR_PROCESS));
+
+ /* We must notify MHI control driver so it can clean up first */
+ mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_SYS_ERROR);
+
+ mutex_lock(&mhi_cntrl->pm_mutex);
+ write_lock_irq(&mhi_cntrl->pm_lock);
+ prev_state = mhi_cntrl->pm_state;
+ cur_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_SYS_ERR_PROCESS);
+ write_unlock_irq(&mhi_cntrl->pm_lock);
+
+ if (cur_state != MHI_PM_SYS_ERR_PROCESS) {
+ dev_err(dev, "Failed to transition from PM state: %s to: %s\n",
+ to_mhi_pm_state_str(cur_state),
+ to_mhi_pm_state_str(MHI_PM_SYS_ERR_PROCESS));
+ goto exit_sys_error_transition;
+ }
+
+ mhi_cntrl->ee = MHI_EE_DISABLE_TRANSITION;
+ mhi_cntrl->dev_state = MHI_STATE_RESET;
+
+ /* Wake up threads waiting for state transition */
+ wake_up_all(&mhi_cntrl->state_event);
+
+ /* Trigger MHI RESET so that the device will not access host memory */
+ if (MHI_REG_ACCESS_VALID(prev_state)) {
+ u32 in_reset = -1;
+ unsigned long timeout = msecs_to_jiffies(mhi_cntrl->timeout_ms);
+
+ dev_dbg(dev, "Triggering MHI Reset in device\n");
+ mhi_set_mhi_state(mhi_cntrl, MHI_STATE_RESET);
+
+ /* Wait for the reset bit to be cleared by the device */
+ ret = wait_event_timeout(mhi_cntrl->state_event,
+ mhi_read_reg_field(mhi_cntrl,
+ mhi_cntrl->regs,
+ MHICTRL,
+ MHICTRL_RESET_MASK,
+ MHICTRL_RESET_SHIFT,
+ &in_reset) ||
+ !in_reset, timeout);
+ if (!ret || in_reset) {
+ dev_err(dev, "Device failed to exit MHI Reset state\n");
+ goto exit_sys_error_transition;
+ }
+
+ /*
+ * Device will clear BHI_INTVEC as a part of RESET processing,
+ * hence re-program it
+ */
+ mhi_write_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_INTVEC, 0);
+ }
+
+ dev_dbg(dev,
+ "Waiting for all pending event ring processing to complete\n");
+ mhi_event = mhi_cntrl->mhi_event;
+ for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
+ if (mhi_event->offload_ev)
+ continue;
+ tasklet_kill(&mhi_event->task);
}
+ /* Release lock and wait for all pending threads to complete */
+ mutex_unlock(&mhi_cntrl->pm_mutex);
+ dev_dbg(dev, "Waiting for all pending threads to complete\n");
+ wake_up_all(&mhi_cntrl->state_event);
+
+ dev_dbg(dev, "Reset all active channels and remove MHI devices\n");
+ device_for_each_child(mhi_cntrl->cntrl_dev, NULL, mhi_destroy_device);
+
+ mutex_lock(&mhi_cntrl->pm_mutex);
+
+ WARN_ON(atomic_read(&mhi_cntrl->dev_wake));
+ WARN_ON(atomic_read(&mhi_cntrl->pending_pkts));
+
+ /* Reset the ev rings and cmd rings */
+ dev_dbg(dev, "Resetting EV CTXT and CMD CTXT\n");
+ mhi_cmd = mhi_cntrl->mhi_cmd;
+ cmd_ctxt = mhi_cntrl->mhi_ctxt->cmd_ctxt;
+ for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++, cmd_ctxt++) {
+ struct mhi_ring *ring = &mhi_cmd->ring;
+
+ ring->rp = ring->base;
+ ring->wp = ring->base;
+ cmd_ctxt->rp = cmd_ctxt->rbase;
+ cmd_ctxt->wp = cmd_ctxt->rbase;
+ }
+
+ mhi_event = mhi_cntrl->mhi_event;
+ er_ctxt = mhi_cntrl->mhi_ctxt->er_ctxt;
+ for (i = 0; i < mhi_cntrl->total_ev_rings; i++, er_ctxt++,
+ mhi_event++) {
+ struct mhi_ring *ring = &mhi_event->ring;
+
+ /* Skip offload events */
+ if (mhi_event->offload_ev)
+ continue;
+
+ ring->rp = ring->base;
+ ring->wp = ring->base;
+ er_ctxt->rp = er_ctxt->rbase;
+ er_ctxt->wp = er_ctxt->rbase;
+ }
+
+ mhi_ready_state_transition(mhi_cntrl);
+
+exit_sys_error_transition:
dev_dbg(dev, "Exiting with PM state: %s, MHI state: %s\n",
to_mhi_pm_state_str(mhi_cntrl->pm_state),
TO_MHI_STATE_STR(mhi_cntrl->dev_state));
@@ -666,8 +782,7 @@ void mhi_pm_st_worker(struct work_struct *work)
mhi_ready_state_transition(mhi_cntrl);
break;
case DEV_ST_TRANSITION_SYS_ERR:
- mhi_pm_disable_transition
- (mhi_cntrl, MHI_PM_SYS_ERR_PROCESS);
+ mhi_pm_sys_error_transition(mhi_cntrl);
break;
case DEV_ST_TRANSITION_DISABLE:
mhi_pm_disable_transition
--
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